It is conventional for a programmable automaton to include one or more such cartridges. For example, a first cartridge may include a read only memory (ROM) containing a so-called "system" program, i.e. a program defining a special language for the programming instructions of the automaton, whereas a second cartridge includes a ROM containing a second so-called "user" program containing the set of instructions required for the process which the automaton is to perform and written in the language under consideration.
In a variant, the or each ROM may be replaced by a battery-backed read/write memory (RAM).
French patent specification number 2 502 357 describes a programmable automaton including a cartridge of the type described above.
The cartridge comprises an essentially rectangular box received in a housing in the front face of the automaton, together with two side tabs fixed to the box and projecting outwardly enabling the box to be grasped for extraction purposes so that the cartridge can be replaced.
However, a cartridge of this type suffers from various drawbacks.
Firstly, since the tabs occupy the entire height of the box, the operator's fingers can be placed in several different positions, and as a result the extraction force might be offset from the cartridge connector. Consequently, torque is set up giving rise to a substantial risk of jamming the cartridge in its housing by rotating it about an axis passing through the collector, and also running the risk of twisting the connector pins and thus making it unusable.
Further, another drawback of such a solution is to increase the size not only of the cartridge per se, but also to increase the empty space which must be reserved for it on the automaton. More precisely, not only must the grasping tabs be in front of the front face plane of the automaton, but also empty spaces must be left on either side of said tabs in order to receive the fingers.
One particular result is that it is possible to juxtapose two such prior art cartridges closely side-by-side, thus further increasing overall size.
In addition, French patent number 2 478 883 describes a system in which cartridge retaining and extracting means are provided on the unit which receives the cartridge instead of on the cartridge itself, said means including a complex mechanism which is frictionally associated with a hinged door.
U.S. Pat. No. US-A-3 140 905 describes an extraction system operating on a similar principle, and applied to the chassis of electronic apparatus.
However, these systems are complex, fragile, and expensive.
The present invention seeks to mitigate the drawbacks of the prior art and to provide a memory cartridge for equipment such as a programmable automaton, which cartridge includes extraction means for ensuring that the extraction force is always exerted level with the collector, and which simultaneously occupies a minimum amount of source in depth, in height, and in width.